Gas turbine cooling arrangement



2,388,99&

s. R. PUFFER ETAL GAS TURBINE COOLING ARRANGEMENT Filed Sept. 14; 1959 Invent ors VP. -.hW -M w. PM) R du H Wm m m a0 S y b Patented Nov. 1 3,.l 94 5 l I UNITED srA'ra s PATENT oFFica GAS runamaooouno ARRANGEMENT Samuel E. Puller,

General Electric Company, a corporation.

New York Lynnfleld Rollin H. Norris, Schenectady, N. Y., assign center, Mara, and on Application September 14', 1939, Serial No. 294,908

4 Claims. (Cl. 6H1) The present invention relates to gas turbine cooling arrangements for cooling the type of gas turbine which includes a bucket wheel usually supported on an overhung portion of a shaft for driving a supercharger or like apparatus as are and has an inner end-portion suitably supported on thebearing and the nozzle box by means including a ring I8. An annular disk I1 is secured used in connection with aircraft power plants and like internal combustion engine plants. The operatinggas in these plants is usuallysupplied from the exhaust manifold of a combustion engine at temperatures orthe order of 700 C. and

- above. These high temperatures cause considerable heating of the bucket wheel and elements adjacent thereto and necessitate the provision of means to keep the temperature of these parts down. v

The object of our invention is to provide an improved.- construction of cooling arrangements for such gas turbines whereby they may be operated safely with gases at high temperature.

For a consideration of what we believe to be novel and our invention, attention is directed to the following description and the claims. appended thereto in connection with the accom panying drawing.

Fig. 1 of the drawing illustrates a turbo supercharger for aircraft in accordance withour invention, and Fig. 2 is a perspective view of a part of Fig. 1.

The arrangement comprises a gas turbine having a bucket wheel I!) secured to an overhung to the outer end of the partition l5 to form together .with the adjacent parts two annular channels l8 and I9. Means are provided for forcing streams of cooling air through these two channels. This means includes a box-shaped channel structure which has an upper end connected to receive air at high velocity. In the present instance the channel structure 20 has an upper endconnected to a-conduit 2| which may receive high velocity air from the slip stream of an aircraft or other suitable source not shown. The structure 20 has a box-shaped. part or box 22 with. partitions 23 and 24. The partitions 23, 24 together with a'rear wall portion 25 are extended downward with the extensions curved to conform to the curved portions of the bearing II and the aforementioned partition i5. The partitions 23, 24 and the wall 25 and theirextensions thus form a channel for directing a portion of the air conducted to the box 22 towards the rear surface of the bucket wheel II), the end portion of a'shaft ll. Gases are supplied to the bucket wheel by means including a nozzle box l2 located on one side of the wheel and arranged to receive exhaust gases from an engine, not shown. The shaft H in the present instance of the curved channel being closely spaced with the rear surfaceof the bucket wheel in. The

partitions 23, 24 together with wall portions of the box 22 define two other channels 26 and 21 to. the left of the partition 23 and to the right of the partition 24 respectively in Fig. 2 for directing streams of air over opposite sides of the bearing l4. Thus the box-shaped channel structure 20 constitutes-a device for receiving compressed air or air at high velocity and for directforms part of a centrifugal type blower or super:

charger l3 or supplying compressed air to a combustion engine. The shaft H is supported by a bearing l4 located between the bucketwheel l0 and the supercharger l3 and having a-righthand' portion in close proximity to and surrounded by the nozzle box l2. During operation,

' .gases are directed by nozzles formed in the box l2 into the spaces formed between the buckets of the wheel ID to be discharged from the latter into the atmosphere. The high temperature of the gases cause considerable heating of the wheel l0 and the bearing ll.- In order to keep the temperature of the wheel IQ and the bearing ll within safe limits-we provide means forreducing radiation from the nozzle boxtowards the bearing and for directinga stream of air towards the wheel and the bearing;

A curved partition or deflector II is disposed.

between the-bearing M and the'nomle box I! ing a portion of the air towards the rear side of the wheel l0 and other portions towards opposite sides of the bearing IL The portion directed to-.

wards the wheel is discharged through the lower 7 portion of the annular channel l9 into the atmosphere. Some'of the gases supplied from the nozzle box l2 to the bucket wheel l0 leak through the annular clearance between" the nozzle box and the wheel into the channel l9 to be discharged into the atmosphere from the latter. The portion of the cooling air directed by the device toward opposite portions of the bearing is discharged through the annular channel l8 into the atmosphere.

What we claim as new and desire to secure by Letters Patent of theUnited States, is:

l. The combination of 'a shaft, a bearing sup-- porting the shaft, 9. gas turbine. having a bucket wheel secured to the shaft on one side of the bearing, a machine driven from the shaft: and arranged on the other side of the bearing, means for supplying gases to the bucket wheel including an annular nomle box surrounding and spaced from the bearing, an annular partition disposed between the bearing and the nozzle box and forming two annular channels therewith, said partition having a cylindrical portion concentrically spaced from the bearing and with an edge closely spaced with the wheel, means including a box-shaped channel structure adjacent the machine and supported on' the partition forming channels for directing separate streams of air towards the rear of the bucket wheel and over diametrically opposite sides of the bearing, the cylindrical portion of the partition being adjacent one of the channels to direct the flow of air therethrough toward the wheel.

2. The combination oi a machine with a bearing and a shaft having an overhung portion supported on the bearing, a gas turbine having a bucket wheel supported on the overhung portion and an annular nozzle box surrounding and spaced from the bearing for directing gases-to the bucket wheel, and means including a channel structure forming a plurality of separate channels and' being disposed between the nozzle box and the machine, one of the channels terminating in close proximity to the wheel to direct a stream of air towards the rear surface of the bucket wheel and other channels being arranged to conduct separate streams of air towards diametrically opposite sides of the bearing, the channels having discharge openings in close proximity of the bearing and the wheel respectively.

3. The combination of a shaft, a bearing supporting the shaft, a gas turbine having a bucket wheel secured to the shaft on one side of the v bearing and an annular nozzle box surrounding in spaced relation an end portion of the bearing for reoting gases to (the bucket wheel, a machine having an element secured to the shaft 40 assasss on the other side of the bearing, and means for reducing radiation of heat from the nozzle box towards the bearing and for coolins the wheel, said means including a partition having an outer straight portion and an inner curved portion between the nozzle box and the machine, and defining two channels therewith, and a channel structure having a wall defined by the partition wheel secured to the shaft on one side of the bearing and a nozzle box for conducting gases to the wheel, a machine having an element supported on the shaft on the other side of the bearing, and means to reduce radiation'of heat from the nozzle box towards the bearing and the machine, said means including a partition located between the machine and the nozzle box and defining a first channel adjacent the machine and a second channel adjacent the nozzle box, the inner edge of the partition iorming a close clearance with the wheel, and a channel structure located substantially within the first channel and having an extension adjacent the bearing and projecting into the second channel, said channel structure forming two passages for conducting separate streams of air towards opposite sides of the bearing and another passage for directing air through the extension towards the wheel.

SABIUEL R. PUFFER. ROLLIN H. NORRIS. 

